(a) Field of the Invention
The present invention relates to a communication device capable of reducing the current consumption of its receiver which is held ready for reception.
(b) Prior Art
The ratio control device has been used to remotely lock and unlock the doors and trunks of motor vehicles or cars. In the case of this radio control device, its transmitter is carried by the driver while its receiver is set in the car. Responsive to data transmitted from the transmitter, the receiver renders an actuator operative to remotely lock and unlock the doors and trunks of cars.
In the case of this conventional radio control device, however, the receiver must be usually kept ready for receiving data because it is uncertain when the data is transmitted from the transmitter while the driver who carries the transmitter leaves his car. In addition, the receiver uses the battery for the car as its power source. The current of the car battery is therefore likely to be consumed by the receiver which must be kept ready for receiving data for a long time. It is thus desired to reduce the current consumption of the receiver which is left ready for data reception.